A respirator is a crucial piece of protective equipment for military personnel. Respirators with a tight seal prevent harmful substances like chemical weapons, smoke, contagious diseases, and environmental hazards.

Source: MIRA Safety
Table of Contents
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01
The Critical Importance of PPE Fit Testing for Military Personnel
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02
The Challenges in Military Respirator Fit Testing
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03
Types of PPE Fit Testing Methods in the Military
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04
Innovations and Technologies in Respirator Fit Testing
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05
Case Studies and Best Practices for Military Personal Protective Equipment Fit Testing
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06
Regulatory Guidelines and Safety Requirements
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07
Practical Solutions and Recommendations
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08
Conclusion: Future-Proofing Respirator Fit Testing in the Military
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09
FAQs
The Critical Importance of PPE Fit Testing for Military Personnel
Military members often need a higher level of protection than many other professions, even health care workers or manufacturing personnel, because battlefield conditions are unpredictable.
The use of PPE that fits perfectly is crucial to military safety in the field. Respirators that fit well with a complete seal are vital for quick-response scenarios. An improper size or fit will allow hazardous aerosols or particulates to enter the respirator face shield exposing soldiers to any of the following risks:
- Limited oxygen
- Aerosols
- Asbestos
- Radon
- Smoke
- Viruses
- Radiological hazards
Respirators can be challenging to fit perfectly. Individuals vary widely, and two people with a similar sized face can have very different measurements across key facial features, like the nose or jaw. Plus, military professionals need respirators that also combine well with eye protection.
Different service members require varying technology integrations for their respirators. These can include specialized safety glasses, helmets and helmet-mounted sights, microphones, earpieces, and body armor. Depending upon the role, an individual may need to use PPE like these and others that integrate seamlessly with their respirator.
Alongside these variables, operational conditions can demand different use of personal protective equipment. Some operations will require a lightweight, agile kit, while others need heavier protective gear. So, you can't just use a basic surgical mask out in the field.
All these considerations are at play when ensuring PPE includes appropriate and correctly-fitted gear. The main reason has to do with the purpose of PPE. Doctors wear gowns or masks to prevent the spread of harmful diseases and bacteria. In the field, military professionals have a different objective: save their lives.

Source: MIRA Safety
The Challenges in Military Respirator Fit Testing
Respirator fit testing is regulated by the National Institute for Occupational Safety (NIOSH) and the Occupational Safety and Health Administration (OSHA). They establish administrative controls and often share sensitive information with other bodies to ensure safety. Respirator fit tests are required for many workplaces that involve exposure to hazards, like healthcare, manufacturing, construction, laboratory work, and first responders.
The military also requires personal protective equipment at work - but faces additional challenges to the civilian workplace.
We'll cover some of the challenges to proper use of personal protective technology, how different types of PPE are tested to meet OSHA standards, and examples of PPE solutions that meet the specific needs of the military.
Variability in Facial Dimensions and Impact of Facial Hair
Many respirators are sold with a range of sizes available, usually ranging from Small to Extra Large. There is far more to fit than size, however.
Numerous studies have indicated that size and the shape of certain facial features affect fit. Factors affecting fit include:
- Face size
- Nose bridge width
- Nose protrusion
- Shape (or contour) of face
- Jaw width
- Gender
- Facial hair
Proper measurement of facial dimensions is crucial to selecting the best respirator for a given person and adjusting it for a safe fit. Personal protective equipment may need to be adjusted for females, who tend to be smaller than males. Similarly, larger people may need additional fittings to ensure that their respirators seal completely.

Source: MIRA Safety
Newer workplace safety investigations have shown that respirator designs don't always take into account facial differences among ethnicities, age groups, and gender. With a more diverse workforce and military in the 21st Century, that means that detailed fit checks will be even more necessary to ensure the health and safety of workers and soldiers alike.
Facial Hair
Even small changes to facial hair can affect a respirator seal. Civilian workplaces can maintain strict regulations surrounding facial hair, but military situations include difficulties.
Some situations may make shaving impossible, due to lack of downtime or access to razors. Another problem is social expectations of different cultures. In some places, it's expected for men to maintain a beard, and this is important for military personnel who interact with the public.
Normal fit checks tend to be performed annually, which does not give appropriate opportunity to adjust for small changes in facial hair growth. Even this small alteration in facial contours can affect a respirator seal, potentially exposing the wearer to risk of injury.
Operational and Environmental Conditions
The type of work that a military member has to perform also affects respirator fit.
Threat level - The particular threat level of a given deployment affects the equipment worn. A high-threat area might demand a bullet proof vest, helmet, and a self-contained breathing apparatus be worn daily. This kind of continued use means that equipment degrades more rapidly and needs additional fit checks and adjustments to maintain compliance.
Environment - The military operates around the globe. Extremely hot temperatures require lightweight, breathable gear that still maintain protection. Cold environments call for insulated protective clothing. Night deployments will require integrations with night vision goggles.
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Types of PPE Fit Testing Methods in the Military
To comply with OSHA standards and other government regulations, fit tests are required annually. These tests ensure that the respirator seal is functioning properly, the respirator is fitted correctly, and PPE training has been given to all wears to ensure they know how to properly use the equipment. Tests also include a medical evaluation to be sure that the wearer is healthy enough to wear a mask correctly without causing adverse health reactions.
There are two main types of fit testing: qualitative and quantitative. We'll explain the differences.
Quantitative Fit Testing (QNFT)
Quantitative Fit Testing (or QNFT) uses specialized equipment to measure the amount of a harmless aerosol compound. The amount of compound in the air is measured, then compared to the amount inside the respirator as it is worn.
This amount is then used to calculate a "fit factor" that determines how well the respirator's seal is functioning. A fit factor of 100 is required for half-face respirators, like N95 respirators used by healthcare workers. A fit factor of 500 is required for full-face respirators, which usually use a specialized filter to purify the air and keep harmful substances from entering the body.
QNFTs tend to be preferred for military settings because of their objective nature. The ratio used to define fit factor is clear, and relies on equipment that can be used consistently in many different settings. It can be challenging to access QNFT gear and qualified testers in the field, making it less accessible for long or remote deployments.
Qualitative Fit Testing (QLFT)
QLFT relies on the feedback of the wearer. A harsh or strong-smelling substance is released into the air and then the wearer tells the tester if they can smell or taste the element. Sometimes, smoke is even used to provide an involuntary cough reaction. Rather than a fit test factor like with quantitative tests, qualitative tests are evaluated by a simple pass/fail metric.
While often used to comply with OSHA guidelines for annual fit checks, the qualitative method is subjective. It relies upon the wearer being tested. Individual sensitivity to smell and taste varies widely and can give inaccurate results. In some extreme cases, people being tested might give unreliable feedback or be pressured to do so by unethical managers. Finally, the qualitative test usually takes up to three times longer to administer than quantitative tests.
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Comparison of QNFT and QLFT

Source: MIRA Safety
Qualitative Fit Testing
Pros |
Cons |
Less expensive option for fit testing |
Subjective and vulnerable to human error |
Easy to administer |
Limited date - pass/fail doesn't provided specific information on fit accuracy |
Accessible - can be performed in many situations without specialized equipment |
Not suitable for high-contaminant scenarios |
Quantitative Fit Testing
Pros |
Cons |
Objective -doesn't rely on the wearer's feedback |
More expensive |
Offers detailed measurements |
Requires specialized equipment and training |
Higher accuracy |
Measurement tools need regular calibration and maintenance |
Innovations and Technologies in Respirator Fit Testing
Quantitative fit testing is a clear preference for military applications because of its accuracy and data-driven evaluation technique. This presents a challenge for military personnel in the field, who require more frequent fit checks but do not always have reliable access to testing equipment and technicians.
Recent innovations have begun to solve some of these problems related to adequate PPE use. We'll explain how.
AI-Driven Facial Scanning Technology
AI has the potential to quickly scan faces and make minute measurements. It can compare these to large datasets and recommend the best respirator for that particular person. It can go further and recommend specific adjustments to ensure a tight seal.
Artificial Intelligence can offer real-time feedback on respirator fit. This allows personnel in the field to make small adjustments to their equipment to maintain a perfect seal. Simply by scanning an individual's face, AI-driven tools can quickly compare measurements to a vast database of measurements to recommend ideal fit adjustments and even predict potential areas of future weakness.
This is crucial for maintaining safety in scenarios where quantitative fit testing may not be accessible but the wearer's face shape may have changed. This can be due to weight loss or gain, facial hair growth or loss, and even injury. In military applications where frequent doffing/donning can stretch or degrade even high-quality equipment, regular fit checks are helpful to ensure that the seal is operating at full effectiveness.

Source: Markus Spiske
As discussed above, there are infinite variations in specific facial shape. With an increasingly diverse military, simplistic fit models that rely only on male Caucasian fit databases are outdated. This has direct implications for how we minimize exposure to hazards for military personnel.
AI-driven tools are also trained on more up-to-date data sets than older fit recommendation rubrics. This means they include measurements taken from women and ethnic minorities. This provides more accuracy for more people. It can also help counteract unconscious bias in fit testers, who may assume all males need a size large while all females need a size small, for example.
Case Studies in AI and Fit Testing
AI facial scans have real-world benefits for respiratory protective equipment fit testing. This technology is already being implemented in hybrid solutions.
The Air Force Medical Service reports early success in a self-serve fit test kiosk in New Jersey. Representatives remarked on the number of man-hours saved because of the new technology. As AI advances to app-based models, even more efficient models are possible.
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Future Directions: Advancements in AI and Technology
AI software is already being trained on large datasets of facial feature measurements to develop new applications for respirator fit testing.
Potential future developments include:
- Real-time feedback in fit testing
- Individualized fit recommendations for specific wearers
- Completely automated fit testing
- Predictive maintenance based on usage patterns
- Remote fit testing
- Direct feedback to respirator designers and manufacturers
This technology is emerging and the military is actively exploring applications for AI to enhance safety and efficiency in the field.
Case Studies and Best Practices for Military Personal Protective Equipment Fit Testing
The military has responded with increased testing protocols as the risk to service members becomes known. These requirements have shifted over time as CBRN threats become more common.
Quantitative Fit Testing Success in Military Environments
QNFT was developed in the 1980s, mainly due to the infection of Condensation Nuclei Counters (CNC), the device used to perform the tests. Quantitative methods are successful in military applications and are considered the gold standard for fit testing under AR 11-34.
The September 11, 2011 terrorist attacks revealed the need for better guidance in military PPE standards and first responder protection. NIOSH developed standards for full-face air-purifying respirators that have been successfully adopted by the army.
Limitations of Qualitative Fit Testing
Qualitative fit testing is allowed by many military units, including the Navy, which has different regulations for half fit and full fit respirators.
It is known that veterans tend to suffer from respiratory disease at a higher rate than the general population. Research is ongoing. The US Department of Veterans' Affairs has dedicated numerous research groups to understanding how breathing in hazardous compounds is affecting veterans' health.
One report of Iraq and Afghanistan veterans showed that exposure to blasts and airborne contaminants in the field led to breathing problems even years later. While many factors affect respiratory health, it's imperative to protect deployed service members as thoroughly as possible from these recognized CBRN threats.
Regulatory Guidelines and Safety Requirements
Military PPE standards differ somewhat from OSHA regulations that apply to civilian workplace hazards. Because the needs for CBRN protection are higher, the military has developed its own guidelines that often vary by service branch.
OSHA Respiratory Protection Standard and Military-Specific Protocols
The US military is technically not under the authority of OSHA regulations. However, the military uses OSHA guidelines as the gold standard in best practices for workplace safety, and then often exceeds those guidelines with additional protections.
The overarching workplace standard is OSHA 1910. This has been integrated by the military. These include regulations like Navy Safety and Occupational Health Program Manual and Army Regulation 385-10.
Recent revisions in the Army Respiratory Health Program require fit testing to be repeated if a service member has physical changes. It also requires that a repair specialist for respirators service the devices.
The military has also adopted OSHA's guidance on positive and negative pressure seal checks. These are performed by closing off the exhalation valve on a full-face respirator. If a slight bulge, but no leakage, is detected in the mask, it's built up "positive pressure" and is considered to be working normally.
Similarly, a negative pressure check is performed by closing off the cartridge port and inhaling, then holding one's breath for 10 seconds. If the mask collapses slightly, it's considered to be working normally.

source: MIRA Safety
Practical Solutions and Recommendations
Operational effectiveness and service person safety is reliant on respirators functioning optimally. As events like September 11 or the Covid-19 pandemic revealed, threats are often unpredictable. Currently, the VA is working to identify and aid many service members who sustained respiratory damage during their tours.
Given the rapidly-changing world and the proven dangers of respiratory contaminants, today's military needs forward-thinking solutions.
Incorporating AI in Military Fit Testing Practices
Artificial intelligence can be integrated with current fit testing protocols to increase affordability, access, and accuracy.
Accuracy - This can be done by training machine learning algorithms on large datasets of facial measurements that are drawn from a diverse population. This helps remedy bias in fit testing by providing a wider range of samples. It also increases accuracy of fit recommendations.
These measurements are not linked to individuals, nor are they actual images of real faces. This protects privacy and addresses concerns about data security.
Access - Recent regulation updates dictate repeated fit checks for physical changes like weight loss or gain. In the field, reliable fit testing equipment and technicians can be impossible to access. There are possibilities to integrate AI-driven monitors directly into deployment gear, meaning that real-time suggestions on fit adjustments could be provided in remote locations.
Affordability - As seen with the New Jersey case study above, AI can augment existing qualitative fit testing procedures. Fit tests can cost between $75-$300 per service member. By automating portions of the process, there will be less need for qualified technicians to spend all their work hours performing fit tests, thereby saving costs.
Ensuring Proper Training and Compliance
Correct training in respirator wear, storage, and maintenance is mandated by regulations like Army Regulation 385-1, Air Force Instruction 90-507, and OPNAVINST 5100.19.
These regulations dictate that anyone wearing a respirator is required to undergo training. While AI-driven tools are vital to an evolving military, the role of human instruction should not be forgotten. Studies have suggested that visual inspections and verbal feedback are important.
Respirators can seem like intuitive equipment. This can lead some wearers to underestimate the importance of a proper fit and a complete seal. AI-driven fit recommendations combined with human training and oversight can help ensure proper compliance with respirator regulations.
Collaboration and Future Policy Development
Researchers are proactively designing applications for AI in the military. NIOSH has issued the Respirator Fit Evaluation Challenge to encourage businesses to develop fit-test technologies providing immediate feedback to wearers. Three phases of the contest have been announced, with prizes ranging from $5,000-$75,000.
Similarly, the Joint Artificial Intelligence Center (JAIC) was created as a subdivision of the Army to explore AI applications in combat. It was recently integrated into the Chief Digital and Artificial Intelligence Office (CDAO), part of the Department of Defense. This Office is in its early stages of development and is at the forefront of integrating AI into military operations and guidance.

Source: CDAO
Conclusion: Future-Proofing Respirator Fit Testing in the Military
Respirators are one of the irreplaceable components of PPE. Respirators provide CBRN protection for high-risk operations in addition to reliable defense from routine contaminants like dust, mold, viruses, and smoke.
Research continues to illuminate how easily damaged the respiratory system can be. Hot wars are on the rise, along with chemical and nuclear threats. The Ebola, and then Covid-19 pandemics increased demand for respirators globally.
In light of these challenges, the need for precise and accessible fit checks for life-saving breathing equipment is obvious. Despite this, many service members are still relying on qualitative fit tests that occur only once a year. Emerging technology like AI can drive both accuracy and affordability, making it possible for the military to provide the highest level of protection to service members as they risk their lives to do their jobs.
Frequently Asked Questions